if you had many bitcoins now, do you sell them or hold?
if you don't sell now and :
Price drop : you will be broken.
More of a broke than broken really. Anyway, you're wrong. Take my situation as an example. I have some coins from 2014 that costed me $500- $700 each. If the price drops I won't be broke, not even close, especially that I've withdrawn my initial investment already, so even if it goes back to $500, which is almost impossible in the current state of cryptocurrencies, I'll still be gaining something.
If I had 1 million USD in BTC now and my coins were bought at $10k a coin I'd be a bit nervous but hold anyway. It's going to be worth much more at some point and it would be a waste to miss that chance.
price goes up later : you will be Billionaire
That would be my choice every time. It's not even greed but reality. The chances of it going back to $13k arte at least twice that of it going to $8k